There has long been an ongoing need for clamping devices, whereby an object can be clamped onto another support element such as a verticle pole. There are many uses for such clamping devices, including providing work space, holding lamps, etc. Such clamping devices generally require the use of a set screw or similar mechanism, meaning that the clamp itself must be made of different parts and that a tool such as a screw driver must be used for installation of the clamp. Also, known clamps frequently provide relatively little mechanical advantage, i.e., the clamping force applied is relatively small compared to the operator force exerted in placing the clamp onto the support element. There is thus a long-felt and longstanding need for an improved clamp which is simple to make, provides a good mechanical advantage, and which is easily manipulated.